<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>

    </style>
</head>
<body>

<script type="text/javascript">
    for(var i=50;i<=150;i=i+10){
        document.write("<img class='pic' width='"+i+"' src='images/1.jpg'/>")

    }

</script>

</body>
</html>